Technologies

Nowadays, to properly design and develop advanced materials capable to preserve for long times their performance under aggressive environments such as power generation plants, renewables, nuclear reactors and electronics of new generation, transport on ground and on space, aeronautics, catalysis, biomedical implants, the optimization of metallurgical processes involved is crucial.

CNR-ISTEC develops geopolymer composites for thermostructural applications, such as: self-supporting cavities; thermal and acoustic insulation; thermal and fire barriers; high temperature coatings and damping; molds and cores for foundry; foams and refractory linings. Geopolymers are chemically bonded materials at T <300 ° C. Being inorganic polymers without water in the structure, they tolerate high temperatures: they are incombustible, do not emit gas or fumes and do not explode.

Silicon nanowires (SiNWs) are 1D structures with diameter ranging from few tens to hundreds of nanometers and length varying from few tens of nanometers to millimiters. SiNWs are fabricated in the labs of the IMM-CNR, Rome Unit,  by using bottom-up technologies such as plasma enhanced chemical vapor deposition (PECVD) at low growth temperature ((≤350°C), allowing the use of plastic and glassy substrates. Their electrical properties can be tuned by controlling the p/n doping during the growth.

Mirrors for space applications, besides featuring suitable optical properties, should be light, resistant to mechanical stresses, and unsensitive to light-shadow thermal cycling. The standard optical materials easily fulfill optical and thermal requirements, but are fragile, and the mirrors must be thick (typically 1/6 of the diameter). For this reason they are heavy, and the only available solution is to lighten them, by removing material from the back side, still preserving the necessary mechanical robustness and optical quality.

Chemical solution deposition of metal-organic precursors have favoured the research and development of thin films of simple and complex oxides such as Pb(Zr,Ti)O3, and Al2O3, up to their industrial application in pyroelectric and capacitor devices. Deposition methods used are spin-on and dip-coating. The advantages of the techniques are:

(i) low cost of equipment and chemicals

(ii) large area deposition

(iii) low crystallisation temperatures

The proposing team that works at CNR ISTEC has recently patented a technology for the production of the Smart Polycrystals (SP), i.e. transparent YAG-based ceramic polycrystals (Y₃Al₅O₁₂) variably doped with rare earths ions and transition metals ions. The SPs solve the problem of the reduction of the efficiency in the solid state laser systems caused by the inhomogeneous heating of the single crystals during the emission process.